Ultimately, the problem with debt is when the lender says “pay up, now.”
Choosing to pay more for something now is one’s own call.
Leveraging assets to improve investments sometimes is smart.
Understanding the risk is critical.
If you own a home outright, and the value goes to $0, at least you have a home.
You don’t want to bring a big check to closing when selling the house.
And you sure don’t want the lender saying “it’s mine now, get out” - which is possible right up to being a day late on the last payment.
Think of the risk involved, though. If the value of your house goes to $0 wouldn’t rather have $100,000 sunk into it instead of $400,000? Especially if it goes to $0 for reasons that force you to leave anyway (like the entire neighborhood goes bad, every employer in the town goes out of business, etc.?